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Graphing Trash Material

  • Lesson
Data Analysis and Probability
Location: Unknown

In this lesson, students participate in activities in which they investigate the data in connection with recyclable materials and develop plans to help the environment.

Most students discard items in the classroom without thinking about what kinds of materials they are throwing away.  This activity increases students' awareness of the number and kinds of materials they discard.  It also encourages them to think about taking action by reusing and recycling some of these items.

Let students work in groups of twos or threes. Have each group save materials they would ordinarily thrown away.  They can use previously discarded classroom items, such as papers, and select clean, safe items.

847 trash can

Have each group pick ten trash items at random.  Lead a discussion on the kinds of materials the students have selected.  Paper and plastic items will be common, but Styrofoam, wood, cloth, metal, and items made of two or more materials, paper and plastic packaging for pencils, for example, may also be found.

Distribute a copy of the Graphing Trash Material Activity Sheet to each group.

pdficon Graphing Trash Material Activity Sheet

Read the title and captions. Help students decide on, and write names for, the remaining categories on the graph. You might want to title one of these categories as "Other."

Have the students predict how many items will be in each category. Students can record their predictions on the sheet.

Help students count their trash materials and fill in the appropriate number of spaces for each category. Have each group report its results to another group and compare their findings.

As they work, circulate and see what kinds of things they are discussing. Prompt them as necessary to notice categories with no items, categories with equal numbers of items, and so on.

Lay the graphs on the floor or on a table. Have students gather around them as you or a group member finish counting the number of items in each category. Compare the totals with the predictions.

Discuss some of the trash items that could be reused or recycled. Let each group draw pictures on the activity sheet of items that could be reused or recycled.

Have a representative of each group show and tell what the group has decided. Use some of the students' ideas for reusing and recycling materials, if possible.



  • Shaw, Jean M. and Firkins, John. September, 1993. The Arithmetic Teacher. p 27-40.


  1. Have students choose ten trash items on another day, graph them according to category of material, and compare the two graphs.
  2. Have students implement some of their ideas for reusing materials. Display the results and pictures in a place where others can see them.
  3. Have each student bring ten clean, safe trash items from home. Discuss possible differences between trash items from home and school. Have students graph their home trash and compare their results with their previously made graphs of classroom trash.
  4. Discuss other ways to categorize and graph trash materials. Students can use some of these ways to arrange trash items on a bulletin-board graph or floor graph.

Learning Objectives

Students will:
  • Gather and categorize data.
  • Create and interpret bar graphs.
  • Develop an action plan for recycling.

NCTM Standards and Expectations

  • Pose questions and gather data about themselves and their surroundings.
  • Sort and classify objects according to their attributes and organize data about the objects.
  • Represent data using concrete objects, pictures, and graphs.

Common Core State Standards – Mathematics

Grade 1, Measurement & Data

  • CCSS.Math.Content.1.MD.C.4
    Organize, represent, and interpret data with up to three categories; ask and answer questions about the total number of data points, how many in each category, and how many more or less are in one category than in another.

Grade 2, Measurement & Data

  • CCSS.Math.Content.2.MD.D.10
    Draw a picture graph and a bar graph (with single-unit scale) to represent a data set with up to four categories. Solve simple put-together, take-apart, and compare problems using information presented in a bar graph.